The ability to quantify isotopic ratios of 135, 133m, 133 and 131m radioxenon is essential for the verification of the Comprehensive Nuclear-Test Ban Treaty (CTBT). In order to improve detection limits, CEA has developed a new on-site setup using photon/electron coincidence (Le Petit et al., 2013. J. Radioanal. Nucl. Chem., DOI : 10.1007/s 10697-013-2525-8.). Alternatively, the electron detection cell equipped with large silicon chips (PIPS) can be used with HPGe detector for laboratory analysis purpose. This setup allows the measurement of β/γ coincidences for the detection of 133 Xe and 135 Xe; and K-shell Conversion Electrons (K-CE)/X-ray coincidences for the detection of 131m Xe, 133m Xe and 133 Xe as well. Good energy resolution of 11keV at 130keV and low energy threshold of 29keV for the electron detection were obtained. This provides direct discrimination between K-CE from 133 Xe, 133m Xe and 131m Xe. Estimation of Minimum Detectable Activity (MDA) for 131m Xe is in the order of 1mBq over a 4 day measurement. An analysis of an environmental radioxenon sample using this method is shown.